1. Field of the Invention
The present invention relates to a block gauge and method of marking ceramic material and more particularly, a block gauge used as a reference gauge in precisely measuring a length and a method of marking a ceramic material used for the block gauge.
2. Background Art
A conventional block gauge is made of a metal material.
A block gauge of a metal material, however, has insufficient corrosion resistance and corrodes easily. For this reason, the handling of such a block gauge requires considerable care. For example, it is necessary to store the block gauge in a completely corrosion-preventive environment, and the block gauge must be handled with corrosion-preventive gloves on.
If corrosion occurs, the surface state of the face indicating the dimension is impaired, thereby making it impossible to maintain the accurate dimension or to bring the block gauge into close contact with another block gauge, in a process called wringing.
In order to enhance the corrosion resistance, the block gauge may be plated with more corrosion-resistant materials, e.g., chrome Cr. However, a plated block gauge increases the number of manufacturing steps and it is difficult to provide a predetermined nominal dimension, thereby making the manufacture of a plated block gauge complicated.
In order to solve problems caused by the metal material, a block gauge made of ceramic material is developing. As marking methods for the block gauge made of a ceramic material, a painting method and a laser radiating method are known.
Although the painting method is a very easy method, a protrusion of the painted material is produced at the marking point having the same effects as corrosion on a metal block gauge.
On the other hand, a recessed mark is obtained by the laser radiating method, but obtaining a mark that has enough contrast to the ceramic material is very difficult.